Kidney cancer refers to cancer that develops within the kidney. The kidney plays an important role in removing excess water, salt and waste products from the blood which then becomes urine, alongside helping control certain processes in the body such blood pressure.

The types of kidney cancer include:

• Renal cell carcinoma – cancer that develops in the kidney’s filtration system (proximal renal tubules). This is the most common type of kidney cancer, accounting for 90% of all kidney cancer diagnoses.
• Urothelial carcinoma – cancer that develops in the transitional cells which line the renal pelvis (where the ureters meet the kidneys). This accounts for 5-10% of all kidney cancer cases and includes Hürthle cell carcinoma
• Wilms tumour – cancer that develops in the kidneys from the abnormal growth of early kidney cells, most commonly in children
• Renal sarcoma – rare cancer that develops in the connective tissue or blood vessels of the kidney. This accounts for less than 1% of all kidney cancer diagnoses

Kidney cancer is the eleventh most common cancer in Singapore, affecting 755 people each year.

Kidney cancer can be described in stages depending on how early or advanced the cancer is.

The TNM system is used to stage kidney cancer and helps doctors understand what your cancer looks like. TNM stands for:

• Tumour – the degree to which the tumour has affected other tissue.
• Node – is a measure of whether lymph nodes have been affected.
• Metastasis – the degree to which the cancer has spread to other organs of the body.